Part-clutch part-throttle in F1

[raymondu999]

This is going to sound like an outright stupid question but I swear it's not a trolling attempt.

In a manual car, when I drive up a slope, if I need to stop at the slope, I will feather the throttle and clutch to a point on part-throttle and part-clutch until the car is at a standstill without using brakes. (For those who've never driven a manual transmission, yes it's possible to be at a standstill on a slope with part-throttle, part-clutch and

F1 has standing starts on sloped grids, such as at Interlagos, where the car starts rolling back if you're purely in neutral. I noticed that on the replays of the start, Vettel's revs were at 15k, rather than the usual 13k for the start - which lead me to wonder - is he doing something with part-throttle, part-clutch to stop the rolling, at the start? That way he just has to react to the lights with his clutch finger, rather than his clutch finger, AND his foot.

Anyone know?

[riff_raff]

Using clutch slip to maintain position on an upward incline is a bad idea, whether you're driving a road car or an F1 car. Slipping the clutch for extended periods generates huge amounts of heat in the clutch discs. The tiny carbon clutches used on F1 cars have very little excess capacity to absorb this kind of heat load without failing. I don't believe F1 cars actually have direct driver control of the clutch. Instead I think they use electronic control of the engine and clutch during a standing start. The carbon clutches currently used in F1 are so small they would likely be destroyed after just one or two standing starts if they were manually controlled by the drivers.

[Kiril Varbanov]

I'm probably not giving any insight, but clutches in F1 are being serviced / repaired after each start. Most of the times this happens after manual inspection and then a decision is made. Often, it is the whole part that is being replaced. The price of F1 clutch is around 10,000 Euros and it weighs about a kilogram, maybe 1.3 kg.

@Ray - I know what you mean - I've done that many times, but the clutch for my Honda is just $100 with the service labor.
In Vettel's case it may be down to a more confidence in anti-slip conditions, hence the higher revs. Or maybe just a small mistake? Otherwise, I agree with what riff_raff says. The tiny carbon fiber disks can take about 900 degrees, but they are easily overheated in slip conditions due to the great friction.
While it is true that 13K revs are a ballpark number, I think you can afford a bit more if you have had a fresh one.
I'd love to hear more thoughts, as honestly I haven't had the time to review drivers' starting settings and procedures.

[Steven]

Just for reference, I checked a few starts, and 15000rpm is not unusual at all.

In fact:
Kimi Raikkonen, Singapore 2013: 14000rpm
Fernando Alonso, Belgium 2013: 15000rpm
Seb Vettel, Korea 2013: 14000rpm

[MOWOG]

The question I have is whether the brakes are somehow involved to keep the car from rolling backwards on an uphill start? Many road cars have a "hill holder" function that preforms just such a function.

In the old days, we used the emergency brake to hold the car. Then when the light turned green, we would juggle the clutch, the accelerator pedal and the hand brake to make a smooth getaway. I think F1 probably has a more sophisticated system than that!

[flynfrog]

left foot brake? Its not like they have to worry about a clutch pedal.

[Richard]

Modern F1 is exactly the same as MOWOG as describes.

No automated releases, so left foot on the brake, right foot on the accelerator, hand held clutch. The only difference is the two stage clutch.

Also I'd expect the drivers couldn't hold the car on the clutch because a slight movement or rocking would trigger the false start sensors.

We had a long thread about starts and clutches a while ago, I'll see if I can find it.

Edit - this is the thread I was thinking of http://www.f1technical.net/forum/viewto ... 10#p197134

Also this one http://www.f1technical.net/forum/viewtopic.php?t=11564

[SectorOne]

In a manual car, when I drive up a slope, if I need to stop at the slope, I will feather the throttle and clutch to a point on part-throttle and part-clutch until the car is at a standstill without using brakes.

Just me who cringed reading that? I can´t imagine that being healthy for the clutch.
I use my foot on the brake instead, it´s easy if you know where the biting point is on the clutch.

[raymondu999]

I'm trying to avoid rolling down during the gap of time between lifting off the brakes and getting on the gas and vice versa - in my country at the red lights some idiots tend to leave only something like 5-10cm clearance. However that's an issue for a different thread.

[SectorOne]

I'm trying to avoid rolling down during the gap of time between lifting off the brakes and getting on the gas and vice versa

That´s what everyone does, if you drive a manual. (you have to) But it should be fairly instant from brake to throttle/clutch.
And once you are on throttle and clutch then you should be moving at that moment and not stay still.

From what i read i took it as you stood on hills using clutch/throttle rather then using the brakes or handbrake.
(and not just a regular take-off sequence from a red light with a slightly tilted road)

[langwadt]

Just for reference, I checked a few starts, and 15000rpm is not unusual at all.

In fact:
Kimi Raikkonen, Singapore 2013: 14000rpm
Fernando Alonso, Belgium 2013: 15000rpm
Seb Vettel, Korea 2013: 14000rpm

I would assume that they use the practice starts, bite point finder etc. to come up with what they believe
is the optimal

and it wouldn't surprise me if an F1 clutch felt like an on/off switch compared to a road car clutch, making any
part clutch very difficult

[Richard]

They undertake a configuration process on the formation lap to find the bite point. Its a combination of pushing buttons and doing wheel spins. The pit crew read the clutch data and tell the driver which clutch settings are needed.

The clutches are vary sharp compared to road cars, but the driver does need to hold the clutch on the bite point for a couple of seconds for the start to avoid wheel spins or getting bogged down.

You can read about it in the thread here viewtopic.php?t=8910#p197134

[raymondu999]

That´s what everyone does, if you drive a manual. (you have to) But it should be fairly instant from brake to throttle/clutch.
And once you are on throttle and clutch then you should be moving at that moment and not stay still.

From what i read i took it as you stood on hills using clutch/throttle rather then using the brakes or handbrake.
(and not just a regular take-off sequence from a red light with a slightly tilted road)

In my country, where traffic congestion is absolutely dreadful, trust me, that gap between brake and throttle is not the slightest bit advised. I don't "stand" on part throttle/clutch, I use it to transition between braking and getaway.

We have "awesome" roads here with up to 30 degrees incline (based on what my iPhone accelerometer told me the last time I checked! ) and even that short delay could mean a dent in your rear fender, and the pain and aggravation of having to take a scolding from someone else.

[PhillipM]

That's what the handbrake is for.

[SectorOne]

I don't "stand" on part throttle/clutch, I use it to transition between braking and getaway.

Everyone does this so i´m confused what you actually do different then the rest of us,